U.S. patent number 10,173,215 [Application Number 15/322,751] was granted by the patent office on 2019-01-08 for flow cell comprising a storage zone and a duct that can be opened at a predetermined breaking point.
This patent grant is currently assigned to THINXXS MICROTECHNOLOGY AG. The grantee listed for this patent is THINXXS MICROTECHNOLOGY AG. Invention is credited to Lutz Weber.
United States Patent |
10,173,215 |
Weber |
January 8, 2019 |
Flow cell comprising a storage zone and a duct that can be opened
at a predetermined breaking point
Abstract
A flow cell having at least one storage zone connected to a duct
for conducting fluid out of, into or/and through the storage zone.
The duct includes a duct section which is delimited by a substrate
and a film joined to the substrate and in which the duct is sealed
and can be opened at a predetermined breaking point by deflecting
the film. The film covers a recess in the substrate which forms the
duct section. A sealing wall that seals the duct and is integrally
joined to the substrate is placed in the recess. The predetermined
breaking point is formed by a breakable joining region between the
film and an edge portion of the sealing wall facing the film. The
dimensions of a peripheral area of the sealing wall which is formed
in the edge portion and runs parallel to the film determine the
surface area of the joining region.
Inventors: |
Weber; Lutz (Zweibrucken,
DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
THINXXS MICROTECHNOLOGY AG |
Zweibrucken |
N/A |
DE |
|
|
Assignee: |
THINXXS MICROTECHNOLOGY AG
(Zweibrucken, DE)
|
Family
ID: |
51136329 |
Appl.
No.: |
15/322,751 |
Filed: |
June 22, 2015 |
PCT
Filed: |
June 22, 2015 |
PCT No.: |
PCT/EP2015/063992 |
371(c)(1),(2),(4) Date: |
December 29, 2016 |
PCT
Pub. No.: |
WO2016/000998 |
PCT
Pub. Date: |
January 07, 2016 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
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US 20170157608 A1 |
Jun 8, 2017 |
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Foreign Application Priority Data
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|
|
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Jul 1, 2014 [EP] |
|
|
14175207 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01L
3/502738 (20130101); B01L 3/502707 (20130101); B01L
3/523 (20130101); B01L 3/50273 (20130101); B01L
2200/0689 (20130101); B01L 2300/0887 (20130101); B01L
2400/0655 (20130101); B01L 2400/0487 (20130101); B01L
2200/028 (20130101); B01L 2300/0816 (20130101); B01L
2400/0481 (20130101); B01L 2200/027 (20130101); B01L
2300/123 (20130101) |
Current International
Class: |
B01L
3/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
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102009009728 |
|
Sep 2010 |
|
DE |
|
102011003856 |
|
Aug 2012 |
|
DE |
|
2647435 |
|
Oct 2013 |
|
EP |
|
2679307 |
|
Jan 2014 |
|
EP |
|
2009071078 |
|
Jun 2009 |
|
WO |
|
Primary Examiner: Siefke; Samuel P
Attorney, Agent or Firm: Lucas & Mercanti, LLP Stoffel;
Klaus P.
Claims
The invention claimed is:
1. A flow cell, comprising: a duct; at least one storage zone
connected to the duct for transporting fluid from, into, or/and
through the storage zone in a flow direction, wherein the duct has
a duct zone delimited by a substrate and by a film connected to the
substrate, in the duct zone the duct is closed off and at a
predetermined breaking point is openable while deflecting the film,
wherein the film covers a clearance in the substrate that forms the
duct zone; and a barrier wall disposed in the clearance and
integrally connected to the substrate and shuts off the duct, the
predetermined breaking point is formed by a rupturable connection
zone between the film and a peripheral portion of the barrier wall
that faces the film, wherein the barrier wall has a thickness,
measured in a direction perpendicular to a planar extent of the
film, that decreases toward the film, dimensions of a peripheral
area of the barrier wall that is parallel with the film and is
formed in the peripheral portion are relevant to a planar extent of
the connection zone.
2. The flow cell according to claim 1, wherein the peripheral area
approximates a line that is perpendicular to the flow
direction.
3. The flow cell according to claim 1, wherein the barrier wall is
a barrier web that traverses the clearance, and said barrier web is
connected to the substrate at ends of the barrier web and on the
peripheral portion that is opposite the peripheral area.
4. The flow cell according to claim 1, wherein the barrier wall, in
cross section, is configured to be triangular or
segment-shaped.
5. The flow cell according to claim 4, wherein the barrier wall has
a flattening that faces the film.
6. The flow cell according to claim 1, wherein the peripheral area
of the barrier wall that is parallel with the film has a bulge that
protrudes counter to the flow direction.
7. The flow cell according to claim 1, wherein the duct, in the
duct zone that has the predetermined breaking point, in relation to
duct zones that are adjacent to the duct zone with the
predetermined breaking point in the flow direction, is widened or
constricted in cross section.
8. The flow cell according to claim 1, wherein the duct is
rupturable by a fluid pressure that bears on the predetermined
breaking point in the flow direction, or by way of mechanical
or/and pneumatic deflection of the film.
9. The flow cell according to claim 1, wherein the film at the
peripheral area of the barrier wall is adhesively bonded and/or
welded to the barrier wall.
10. The flow cell according to claim 1, wherein the film is clamped
to the peripheral area of the barrier wall by a movable clamping
element that is connected to the flow cell.
11. The flow cell according to claim 1, wherein the substrate is
plate-shaped and the clearance is open toward a planar area of the
plate-shaped substrate.
12. The flow cell according to claim 1, wherein the predetermined
breaking point lies in a projection zone of the storage zone, the
projection zone being for a projection perpendicular to a planar
area.
13. The flow cell according to claim 1, wherein the duct has a
plurality of predetermined breaking points, wherein a drying
reagent is enclosed between two predetermined breaking points.
14. The flow cell according to claim 1, wherein the storage zone is
delimited by the substrate and a film thermoformed in the storage
zone and disposed on one side of the substrate, and is connected to
the duct zone by a duct portion, and the film that delimits the
duct zone is disposed on the other side of the substrate.
15. The flow cell according to claim 14, wherein the film that
delimits the storage zone is an aluminum-plastics laminate having a
plastics layer that faces the storage zone.
16. The flow cell according to claim 14, wherein at least one side
of the substrate has a surface structure that facilitates
connection to the film.
17. The flow cell according to claim 16, wherein the surface
structure includes trenches.
18. The flow cell according to claim 1, wherein the film that
delimits the duct zone is a plastics film.
19. The flow cell according to claim 1, wherein the plastics film
is covered by an aluminum-plastics laminate.
20. The flow cell according to claim 13, wherein the film that
delimits the duct zone is a contiguous film that delimits a
plurality of storage zones.
Description
The present application is a 371 of International application
PCT/EP2015/063992, filed Jun. 22, 2015, which claims priority of EP
14 175 207.1, filed Jul. 1, 2014, the priority of these
applications is hereby claimed and these applications are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a flow cell, in particular for analyzing
or/and synthesizing substances, having at least one storage zone
which is connected to a duct for transporting fluid from, into,
or/and through the storage zone, wherein the duct has a duct zone
that is delimited by a substrate and by a flexible film which is
connected to the substrate, in which duct zone the duct is closed
off and at a predetermined breaking point is openable while
deflecting the film.
A flow cell of such type in which the duct is connected to a
storage chamber that is to be emptied by way of the duct is derived
from WO 2009/071078 A1. The storage chamber is formed by a
thermoformed zone of the otherwise planar film that delimits the
duct zone. The film is composed of an aluminum layer having a
plastics coating that faces the internal side of the storage
chamber. Outside the storage chamber and the duct zone, and at the
predetermined breaking point, the film is adhesively bonded or/and
welded to a planar surface of the substrate or to a further film
that covers the latter.
The predetermined breaking point that is established by welding
or/and adhesive bonding between the plastics coating of the film
and the planar surface of the substrate, in terms of the planar
extent of the former, is capable of being metered only with great
difficulty. Influences caused by variations result above all from
the behavior of the plastics coating of the film during welding,
from the distribution of the temperature generated by a welding
tool, from the achievable welding track width of approx. 1 mm, from
the accuracy in positioning the welding tool and thus from the
reproducibility of the spacing of the predetermined breaking point
from the storage zone. The force required for rupturing the
predetermined breaking point varies accordingly in an undesirable
manner.
SUMMARY OF THE INVENTION
The invention is based on providing a new flow cell of the type
mentioned at the outset, having a duct zone that has a
predetermined breaking point, wherein the force for rupturing the
predetermined breaking point is in a tighter tolerance range.
This object is achieved according to the invention in that the film
covers a clearance in the substrate that forms the duct zone, and a
barrier wall which is integrally connected to the substrate and
which shuts off the duct is disposed in the clearance, that the
predetermined breaking point is formed by a rupturable connection
zone between the film and a peripheral portion of the barrier wall
that faces the film, and that the dimensions of a peripheral area
of the barrier wall that is parallel with the film and is formed in
the peripheral portion are relevant to the planar extent of the
connection zone.
By way of concentrating the connection zone that forms the
predetermined breaking point according to the invention to the
peripheral area of the barrier wall that reaches up to the film,
the connection zone, independently of the welding conditions, has a
defined extent and position. Variations in the force required for
rupturing the predetermined breaking point are accordingly
minor.
As is explained below, the mentioned peripheral area may
approximate a line that is perpendicular to the flow direction of
the fluid.
Preferably, the duct is openable by way of a fluid pressure that
bears on the predetermined breaking point, or by way of mechanical
or/and pneumatic deflection of the film. While a fluid pressure may
be built up e.g. by squeezing a storage chamber having a flexible
film wall, an operating apparatus that is provided for the flow
cell may be employed for mechanically or/and pneumatically
rupturing the predetermined breaking point.
It is to be understood that the film at the peripheral portion may
be adhesively bonded or/and welded to the peripheral area of the
barrier wall. Alternatively or additionally, a releasable clamping
connection could be established by way of a clamping element that
acts on the film and is movably connected to the flow cell.
The barrier wall is preferably produced in one operational step,
conjointly with the injection molding of the substrate.
In one particularly preferred embodiment of the invention, the
peripheral area of the barrier wall terminates flush with the
opening periphery of the clearance that is formed in the substrate.
In this way it may be ensured that the barrier wall by way of the
peripheral portion thereof that faces the covering film reaches up
to the film, and that the film may be adhesively bonded or/and
welded in one operational step to both the substrate as well as to
the peripheral portion of the barrier wall.
While it is possible for the barrier wall to be configured so as to
be annular, while blocking a corresponding radial fluid flow, the
barrier wall in the preferred embodiment is configured as a barrier
web that traverses the clearance in the substrate, said barrier web
at the ends thereof being connected to the substrate.
The thickness of the barrier wall preferably decreases toward the
covering film, in particular in such a manner that the film bears
on the peripheral portion of the barrier wall in only a linear
manner.
Accordingly, the barrier wall in the cross section may be
configured so as to be triangular or segment-shaped. In one further
embodiment, the peripheral portion of the barrier wall bears on the
film by way of a flattening. The length of the flattening in the
flow direction, and thus the length of the predetermined breaking
point in this direction, is preferably less than 0.5 mm, in
particular less than 0.1 mm, optionally less than 0.05 mm.
The clearance preferably opens toward a planar area of a preferably
plate-shaped substrate, and the film that covers the clearance is
preferably a planar film.
In one further embodiment of the invention, the duct, in that duct
zone that has the predetermined breaking point, in relation to duct
zones that are adjacent thereto, is widened or constricted in the
cross section. The barrier web can be lengthened or shortened
accordingly. Since the rupture force of the predetermined breaking
point depends on the geometry of the connection zone between the
film and the barrier web, the rupture force may be set by a
suitable choice of the widening or the constriction. The rupture
force exerted by a mechanical actuator that compresses the storage
zone is preferably less than 20 N, in particular less than 10 N,
optionally less than 5 N.
The predetermined breaking point in the case of a projection that
is perpendicular to the plate plane of the substrate preferably
lies in the projected zone of the storage chamber. In this
space-saving embodiment the storage chamber is optionally located
on one side of the plate-shaped substrate, while the clearance that
forms the duct zone is disposed on the other side of the plate.
In particular in the case of the latter embodiment, the storage
chamber may be composed of a film that has an aluminum layer having
a plastics coating that faces the internal side of the storage
chamber, wherein the plastics coating is applied in a planar manner
to the substrate by welding or adhesive bonding, and the
predetermined breaking point is formed between the plate-shaped
substrate and a cover film from plastics, preferably from the same
plastics as the substrate. Thermal welding, ultrasonic welding, or
laser welding may be considered for producing the predetermined
breaking point from identical plastics material, for example.
In a further design embodiment of the invention, the duct may have
a plurality of predetermined breaking points, and a functional
element of the flow cell, such as a drying reagent, for example,
may in particular be disposed downstream of a predetermined
breaking point.
Moreover, the drying reagent may be enclosed between two
predetermined breaking points.
A film that delimits the storage chamber may be identical to a film
that delimits the duct zone, in particular when the storage chamber
and a duct zone that is connected to the storage chamber are both
disposed on one side of a plate-shaped substrate.
The invention will be explained in more detail hereunder by means
of exemplary embodiments and of the appended drawings which refer
to these exemplary embodiments. In the drawings:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a flow cell having a plurality of fluid transport
ducts according to the invention, in a front view;
FIG. 2 shows the flow cell of FIG. 1 in a rear view, without a
cover film;
FIG. 3 shows a duct zone of a transport duct of the flow cell of
FIG. 1, having a predetermined breaking point, partially without a
cover film;
FIG. 4 shows various exemplary embodiments of a fluid storage unit
that is usable in a flow cell, having a transport duct according to
the invention that is connected to the fluid storage unit;
FIG. 5 shows three further exemplary embodiments according to the
invention, for configuring predetermined breaking points in
transport ducts;
FIG. 6a shows a transport duct having two predetermined breaking
points;
FIG. 6b shows a transport duct having an annular predetermined
breaking point;
FIG. 7 shows transport ducts according to the invention, having a
drying reagent that is disposed so as to be adjacent to the
former;
FIG. 8 shows transport ducts having predetermined breaking points
which may be ruptured by external actuators;
FIG. 9 shows a transport duct according to the invention that is
connected to two storage chambers;
FIG. 10 shows transport ducts according to the invention, for
filling a storage space of a flow cell;
FIG. 11 shows storage units which are provided to be partially
filled by transport ducts according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
A microfluidic flow cell, shown in FIG. 1, which is connectable to
an operating apparatus (not shown) comprises a substantially
plate-shaped substrate 1 which is integrally produced from plastic
by the injection-molding method, for example from PP, PE, COC, PC,
PMMA, or from a mixture of these plastics.
The substrate, on the side thereof that is visible in FIG. 1, by
way of part of its plate area is adhesively bonded or/and welded to
a film 2. On that side of the substrate 1 that faces away from the
former, the entire plate area is connected to a planar film 3 which
covers and shuts off clearances in the substrate 1 that are open
toward this plate area.
Thermoformed zones of the film 3 in the example shown form three
storage chambers 4, 5, and 6 for receiving reagent liquids. The
film 2 is composed of an aluminum-plastics laminate, the aluminum
layer thereof that points toward the outside forming a vapor
barrier to the reagent liquids in the storage chambers.
The cover film 3 in the example shown is composed of the same
plastics material as the substrate 1, or else optionally of an
aluminum-plastics laminate.
As is shown in FIG. 2, the storage chamber 4 by way of a duct 7 is
connectable to a chamber 10 for receiving a specimen substance to
be examined. The specimen chamber 10 in turn by way of a duct 11
and a reaction or detection zone 12 for examining the specimen
substance is connected to a waste chamber 13. The storage chambers
5 and 6 by way of ducts 8 and 9 may be connected to the duct
11.
The ducts 7 and 9 each have a widened duct zone 14, separately
illustrated in FIG. 3, in which the duct in the flow direction is
closed off and an unlockable predetermined breaking point is
formed.
A clearance 15 which forms the respective duct zone 14 and is
relevant to the size of the duct cross section is traversed by a
barrier web 16 that in the example shown has a triangular cross
section. A peripheral portion 17 of the barrier web 16 that faces
the cover film 3 is flush with the planar plate area 18 of the
substrate 1 that is adjacent to the clearance 15, and is connected
to the cover film 3. The barrier web 16 that is integrally
connected to the substrate 1 in this way completely blocks the
respective duct.
The cover film 3, which is adhesively connected or/and welded to
the substrate 1, in the zone of the peripheral portion 17 is also
connected to the barrier web 16, wherein this connection forms a
rupturable predetermined breaking point. In the case of a prevalent
fluid pressure that may be generated by compressing a thermoformed
zone of the film 2 and by squeezing the respective storage chamber
4, 5, or 6, the connection between the barrier web 16 and the cover
film 3 is ruptured, while deflecting the cover film 3.
The peripheral portion 17 of the barrier web 16 forms a connection
zone that in terms of the dimensions thereof is defined and that
enables a reproducible closure strength and thus reliable rupturing
of the predetermined breaking point at a specific fluid pressure.
The length of the peripheral portion 17 is preferably <0.5 mm,
in particular <0.1 mm, optionally even <0.05 mm.
In the example shown, the film 3 is adhesively bonded or/and welded
to the barrier web 16. Additionally or alternatively, a clamping
connection between barrier web 16 and cover film 3 is also to be
considered, as is discussed further below.
For the sake of simplicity, further details of the flow cell shown
in FIGS. 1 and 2 are not described herein. It is to be understood
that a flow cell having a duct of the type as is included in a
plurality thereof in the flow cell of FIGS. 1 and 2 may also be
constructed in a manner entirely different from that of the flow
cell shown in FIGS. 1 and 2, and in the extreme case may, for
example, have a duct of this type only as a singular functional
part.
FIG. 4 in fragments shows flow cells having a storage chamber 19
and a duct 20 having a predetermined breaking point on a barrier
web 16. The storage chamber 19 is delimited by a film 2 which is
adhesively bonded or/and welded to a plate-shaped substrate 1 on
one side of the latter. A cover film 3 that is adhesively bonded
or/and welded to the plate-shaped substrate 1 on the other side of
the latter, while delimiting the duct 20, shuts off a duct
clearance 15 in the substrate 1 that is connected to the storage
chamber 19.
According to FIG. 4A, an actuator ram 22, acting on a thermoformed
zone 21 of the film 2 that forms the storage chamber 19, of an
operating apparatus (not shown in more detail) in terms of the
dimensions of said actuator ram 22 is configured so as to be
narrower than the thermoformed zone 21, such that the latter
laterally buckles in a defined manner when fluid is squeezed out of
the storage chamber 19, thus enabling a controlled buildup of
pressure for opening the predetermined breaking point.
In a projection that is perpendicular to the plate plane of the
substrate 1, the barrier web 16 is located in the duct 20 within
the projected zone of the storage chamber 19. The storage unit and
the predetermined breaking point may thus be accommodated in a
space-saving manner in a narrow zone of the flow cell.
In the case of the exemplary embodiment of FIG. 4b, a storage
chamber 19 between a film 2 and a substrate 1 is not formed by a
thermoformed zone 21 of the film 2 alone, but also by a clearance
24 in the substrate. The clearance 24 and the geometry of the
actuator ram 22 are chosen such that complete emptying of the
storage zone is possible in that the film 21 in the terminal
position of the actuator ram 22 is deformed such that said film 21
largely bears on the contour of the clearance 24. For this purpose,
the contour of the actuator ram 22 in relation to the contour of
the clearance 24 is recessed by a factor corresponding to double
the thickness of the film 2.
According to the exemplary embodiment of FIG. 4c, such a clearance
24 in the substrate 1 is singularly relevant to the volume of a
storage chamber 19.
The exemplary embodiment of FIG. 4d corresponds to the exemplary
embodiment of FIG. 4a. A movable element 25 may be retained
manually or by an operating apparatus in a closure position, or
said movable element 25 is fixedly yet releasably connected by
means not shown, such as by undercuts or snap-fit closures, to the
substrate 1 such that the predetermined breaking point on the
barrier web 16 is impossible to be forced open by a buildup of
pressure in the duct 20 with the aid of an actuator ram 22. The
predetermined breaking point may only be ruptured in a position in
which the element 25 is retracted from the retaining position shown
in FIG. 4d. The element 25 may be retracted manually or by the
operating apparatus. When the movable element 25 is used, adhesive
bonding or welding of the predetermined breaking point may be
dispensed with. By retracting the element 25, the force required
for unlocking the predetermined breaking point is reduced by the
amount that would be necessary for rupturing a welded or adhesively
bonded connection.
The exemplary embodiment of FIG. 4e corresponds to the exemplary
embodiment of FIG. 4c, except for a further film 26 which forms a
vapor barrier to fluid that reaches the duct 20 from the storage
unit 19. The film 26 is composed of aluminum, for example, and has
an integrated adhesive layer that is sensitive to pressure, for
example. Alternatively, the film 26 may be connected to the film 3
only in a localized manner and not in the zone of the predetermined
breaking point.
Such a barrier film 26 is advantageous in particular in the case of
the exemplary embodiment of FIG. 4f, in which a storage chamber 19
is formed by a clearance 24 that continues through a substrate 1,
the storage content thus coming into direct contact with the cover
film 3. A duct portion 23 that connects the storage chamber 18 to
the clearance 15 may be omitted in the case of the exemplary
embodiment of FIG. 4f.
Exemplary embodiments shown in FIG. 5 correspond to the exemplary
embodiment of FIG. 4c, except for the design of the cross section
of a barrier web that forms the predetermined breaking point.
According to FIG. 5a, a barrier web 16a in the cross section is not
configured so as to be triangular but semicircular. In the case of
such a cross section, the barrier web also bears on the cover film
3 in a linear manner. Such a barrier web during injection molding
of the substrate 1 may advantageously be produced at a lower
injection pressure than a barrier web that is triangular in the
cross section.
FIG. 5b shows a barrier web 16b having a flattening that faces the
cover film 3. The flattening forms a planar peripheral area of the
barrier web 16 that is parallel with the film 3, wherein this
peripheral area is congruent with a connection zone between the
film 3 and the barrier web 16, the connection zone forming a
predetermined breaking point. The front and the rear edge of the
flattening, when viewed in the flow direction, delimit the
connection zone.
In the case of the exemplary embodiment according to FIG. 5a the
peripheral area of the barrier web 16 that is parallel with the
film 3 is in each case approximated to a line which extends in a
transverse manner to the direction of the fluid flow.
FIG. 5c shows a barrier web 16c having a peripheral portion 17c
that faces the film 3 (not shown), on which peripheral portion 17c
a peripheral web 40 that in relation to the remaining barrier web
is narrower and that has a correspondingly narrow peripheral area
41 that is parallel with the film 3 is formed. Such a step-shaped
barrier web may advantageously be produced at low tooling
complexity by the injection-molding method. The peripheral area 41
that is parallel with the film 3, in the longitudinal center of the
peripheral web 40, has a bulge 42 that is formed by a protrusion of
the peripheral web 40. This bulge 42, projecting counter to the
flow direction, during rupturing of the predetermined breaking
point forms an initial zone which promotes symmetrical rupturing of
the predetermined breaking point from the web center toward the
sides, thus contributing toward high reproducibility of the force
that is required for rupturing the predetermined breaking
point.
FIG. 6a shows an exemplary embodiment which largely corresponds to
FIG. 4c but in the case of which two predetermined breaking points
instead of only one are formed by two barrier webs 16 and 16'.
Particularly tight closure of the storage chamber 19 may be
achieved by the two predetermined breaking points. The fluid
pressure that is required for rupturing the predetermined breaking
point may be dissimilar, that is to say be higher for the second
predetermined breaking point at 16' than for the first
predetermined breaking point at 16, for example, this being
adjustable potentially by way of dissimilar widths of the
predetermined breaking points, for example.
FIG. 6b shows an exemplary embodiment which is similar to that of
FIG. 4c, in which, deviating from the latter, the opening of a duct
portion 23 that connects the storage chamber 19 to the clearance 15
is surrounded by an annular barrier web 16a. The annular barrier
web 16a may be configured as an entire ring or as a segment of an
entire ring.
FIG. 7 shows exemplary embodiments in which a drying reagent 27 is
disposed downstream in a duct 20 of a predetermined breaking point.
This drying reagent may advantageously be suitably re-dissolved by
way of a liquidizing reagent that is retrieved from a storage
chamber 19. Prior to the predetermined breaking point being opened,
the drying reagent is expediently isolated from the storage chamber
19.
In the case of the exemplary embodiment of FIG. 7b, a predetermined
breaking point, which is formed by a further barrier web 16', is
yet again disposed downstream of the drying reagent. On account
thereof, environmental influences are kept away even more
effectively from the drying reagent during storage.
FIG. 8 in fragments shows exemplary embodiments of flow cells, in
which separate installations for rupturing a predetermined breaking
point that is formed by a barrier web 16 are provided.
In the case of the exemplary embodiment of FIG. 8a, a weak spot is
formed in a substrate 1 by way of a clearance 28 in such a manner
that a cover film 3 by way of a protrusion 29 according to the
dashed line 30 may be deflected with the aid of an actuator ram 22,
and the predetermined breaking point which is formed at 16 may be
ruptured, or in the case of an opened predetermined breaking point
the throughflow cross section of the duct 20 may be enlarged,
respectively. In particular, emptying of the storage unit 19 may be
performed at low pressure by way of this separate opening action of
the predetermined breaking point. Moreover, the flow resistance of
the predetermined breaking point may advantageously be regulated
when the latter is opened.
In the case of the exemplary embodiment of FIG. 8b, an inlet duct
31 for a pressurized gas that deforms the substrate in a
corresponding manner is formed instead of a mechanical actuator ram
22.
In the case of the exemplary embodiment of FIG. 8c, two weak spots
for deflecting a film 3 are provided so as to be disposed ahead and
behind a predetermined breaking point, when viewed in the flow
direction, wherein clearances 28 and 28' that form weak spots are
interconnected by way of a duct 32. A film 2 may be dented by
actuator ram 22 and 22' such that a gas pressure that deforms the
substrate 1 and deflects the film 3 according to the dashed line 30
is created in the clearances 28, 28'.
The exemplary embodiment of FIG. 8d, having only one clearance 28
and one actuator ram 22, operates based on the same principle.
FIG. 9 shows an exemplary embodiment having a storage chamber 19
and a further storage chamber 19'. A deformation of a film 2 by way
of an actuator ram 22 leads to a buildup of pressure in the chamber
19' and thus to two predetermined breaking points that are formed
by barrier webs 16 and 16' being opened. The transport of reagent
from the storage chamber 19 thereafter, by virtue of the already
opened predetermined breaking points, may be performed in a more
controlled manner and at lower pressure.
FIG. 10 in fragments shows flow cells having a storage chamber 33
that is only partially filled with a fluid 34, the former being
isolated by way of a barrier web 16 that forms a predetermined
breaking point. The storage chamber 33 may be filled with a further
fluid, for example a fluid to be analyzed, by way of a duct 20. In
the case of a pressure buildup by an inflowing fluid as indicated
according to the arrow 35, a predetermined breaking point that is
formed on the barrier web 16 is ruptured. In the case of a further
pressure buildup, the gas of the air-filled or gas-filled part-zone
of the storage space 33 is initially compressed, the fluid reaching
the storage space where said fluid may mix and optionally react
with the fluid 34 that is stored in said storage space. After
filling, a drop in pressure leads to the compressed air escaping in
the direction that is counter to the arrow 35. This may be
simultaneously performed by a plurality of storage zones 33 if and
when the adjacent duct zones 20 thereof are connected to a pressure
source and to a fluid source. After filling and the buildup of
pressure, the fluid mix is prevented from flowing back by the
barrier web 16.
The volume of the storage chamber 33 is in part formed by a
continuous clearance 24 in a substrate 1, and furthermore by a
thermoformed zone 21 of a film 2 which may be composed of an
aluminum-plastics laminate or only of plastics, and may be produced
by injection-molding.
The storage chamber 33 in the case of the exemplary embodiment of
FIG. 10b contains a drying reagent 37.
The exemplary embodiment of FIG. 10c differs from the exemplary
embodiment of FIG. 10a in that the storage volume of the storage
chamber 33 is formed exclusively by a substrate 1 having a bulge
36.
Such a bulge is absent in the case of the exemplary embodiment of
FIG. 10d. A clearance 24 in the plate-shaped substrate 1 which is
open on one side is exclusively relevant to the volume of the
storage chamber 33.
In the case of the exemplary embodiment of FIG. 10e, the clearance
24 is continuous, and is covered on both sides by a film 2 or 3,
respectively.
In the case of an exemplary embodiment shown in FIG. 11, a storage
chamber 33 is partially filled with a fluid 34. A pipeline 37 which
is submerged in the fluid 34 protrudes into the storage chamber 33.
The pipeline 37 is connected to a duct 20 that is closed off by a
barrier web 16.
After a predetermined breaking point that is formed on the barrier
web 16 has ruptured, a specimen fluid to be examined by way of the
duct 20 and the pipeline 37 may be directed into the storage
chamber 33 where the specimen fluid comes into contact with a fluid
34 that forms a reagent.
A conveying pressure that bears on the specimen fluid in order for
the predetermined breaking point to be ruptured, after opening the
latter, ensures that the air that when viewed in the flow direction
is located behind the barrier web 16 in the duct 20 and the
pipeline 37 is displaced, said air rising in the fluid 34. Specimen
fluid that finally enters the storage chamber 33, due to a
compression of the air above the fluid level of the fluid 34,
ensures a buildup of pressure in the storage chamber 33.
In the case of the conveying pressure being reduced, a mixture of
the specimen fluid and of the reagent fluid 34 therefore flows back
into the pipeline 37 and optionally into the duct 20. By way of
alternatingly increasing and lowering the conveying pressure the
mixture may be moved accordingly and be further homogenized by the
movement.
By way of further lowering the conveying pressure, the mixture by
way of the pipeline 37 and of the duct 20 may finally be discharged
to a part of the flow cell that further processes said mixture, or
the latter for the purpose of analysis, for example a visual
analysis, remains in the storage chamber 33.
The same construction of a storage chamber may also be used for
re-suspending a drying reagent such as the drying reagent 37 of
FIG. 10b that is provided in the storage chamber.
The construction according to FIG. 11 may also be utilized merely
for emptying the storage chamber 33, in that pressurized gas is
infed by way of the duct 20 and is compressed above the fluid level
in the storage-chamber zone. The pressurized gas may subsequently
force the fluid 34 out of the storage chamber 33 for evacuation
into the pipeline 37 and into the duct 20.
A film 21 that forms the storage unit may be configured so as to be
elastically deformable such that the volume of the storage chamber
33 may be enlarged by the conveying pressure such that
comparatively large specimen amounts may be processed. Furthermore,
the buildup of pressure in the storage chamber 33 is reduced by way
of the enlargement of the volume.
The exemplary embodiment of FIG. 10b differs from the exemplary
embodiment of FIG. 10a in that there is a filling duct 38 that
opens into the storage chamber 33, through which filling duct 38 a
reagent may be filled into the storage chamber, for example by
means of manual or automatic pipetting, or by means of a needle
that penetrates the filling duct. It is to be understood that air
that is displaced during this procedure must be able to escape from
the storage chamber 33. After filling, the filling duct 38 may be
sealed by welding, adhesive bonding, or/and by means of a closure
plug.
In the case of an exemplary embodiment that is illustrated in FIG.
11c, a second duct 20' having a barrier web 16' is provided. The
duct 20' is connected to the storage chamber 33 by way of a passage
39 which opens out above the fluid level of the fluid 34.
Once predetermined breaking points that are provided on the barrier
webs 16, 16' have been ruptured, a specimen fluid may be infed by
way of the duct 20 and of the pipeline 37, wherein displaced air
may escape through the passage 39 and the duct 20'. By way of
pressurized gas that comes to bear on the fluid level in the
storage chamber 33 by way of the duct 20, a mixture of specimen
fluid and reagent that has been formed may be removed almost
without residue from the storage chamber 33 by way of the pipeline
37 and the duct 20.
The plastics coating of the films 2 that are formed from an
aluminum-plastics laminate, as in the flow cells described above,
is preferably composed of the same plastics material as is the
respective substrate 1.
The fluid in the storage chambers described above, instead of being
a liquid, may also be merely air or another pressurized gas that is
usable for transporting fluid in the flow cell.
The substrate, in particular on that side thereof that faces the
film 2, is expediently provided with a surface structure, for
example with trenches, that facilitates the connection to the film
2, 3. The trenches may encircle the storage zone, in particular.
Preferred cross-sectional dimensions of the trenches are
0.1.times.0.1 mm.sup.2 to 1.times.1 mm.sup.2. One to three trenches
are advantageously formed. During adhesive bonding or welding, the
adhesive or the fused plastics layer of the film 2 may penetrate
the trenches and engage therein, this improving the adhesion of the
film to the substrate 1.
In order for the cover film 3 to be connected to the substrate, in
particular laser welding or thermal bonding may be considered, even
bonding facilitated by solvents. Using this method, connection
zones of the predetermined breaking points that have constant
dimensions and constant strength may be achieved.
* * * * *